1. Field of the Invention
The present invention provides a sample heater assembly that provides an enhanced ability to detect low volatility agents, such as particular chemical warfare agents.
2. Brief Description of the Related Art
Low volatility agents (LVA), particularly in the chemical warfare agent nerve agent class of VX, pose a very toxic and persistent hazard to conventional military forces and possibly to civilian populations. Commonly known as a weapons of mass destruction (WMD), these chemical warfare agents are potentially employed as a tactical or terror weapon in various military scenarios, such as being deployed in military actions for effective terrain denial using a variety of dissemination mechanisms including grenades, mortars, mines, rockets, bombs and long-range projectiles and missiles. Likewise, terrorists employing these or other dispersal devices could also disperse these hazardous compounds. Although these low volatility agent hazards normally produce minimal vapor inhalation hazard, if properly configured, high explosive mechanisms and special configuration sprayers can produce airborne droplets and aerosols in addition to significant liquid ground deposition contamination. In such forms, these hazards are generally liquids and exhibit physical/chemical properties quite different from respiratory hazard chemical warfare agents (CWAs), e.g. Sarin (GB). Low vapor pressure hazards, such as low volatility agents, are difficult to detect using currently known fielded vapor detectors.
These low volatility agents, because of their low vapor pressures, are difficult to detect with the current chemical vapor detection systems such as the Improved Chemical Agent Monitor (ICAM) and the M256A1 Chemical Agent Detector Kit. The M256 detector Kit, for example, detects Sarin (GB) to a sensitivity level of 0.005 mg-min/m3 using a very specific eel enzyme cholinesterase. This enzyme is similar to human acetyl cholinesterase and its activity is reduced with exposure to organophosphorus hazards, such as Sarin (GB) or VX. As Sarin is approximately 2000 times more volatile than VX, to accomplish VX binding in the vapor state to the eel enzyme cholinesterase in the M256 Chemical Detector Kit, more vapor molecules are necessary to effect detection. The M256A1 Chemical Agent Detection Kit, including its pertinent M256 Chemical Agent Detector, is described in Department of the Army Technical Manual, TM 3-6665-307-10, titled A Operator=s Manual for Chemical Agent Detector Kit, M256 (6665-01-016-8399) and M256A1 (6665-01-133-4964)@, September 1985, which also describes the Mustard Agent Heater Assembly (MAHA) of the M256A1 Chemical Agent Detection Kit. Additionally, the Improved Chemical Agent Monitor (ICAM) is described in Army Technical Manual TM 3-6665-331-10, and the M8 Chemical Agent Detection Paper is described in army supply Bulletin SB 3-6665-2. The disclosure of each of these references for the M256A1 Chemical Agent Detection Kit, M256 Chemical Agent Detector, Mustard Agent Heater Assembly, Improved Chemical Agent Monitor, and M8 Chemical Agent Detection Paper are incorporated herein by reference in their entirety.
As the threat of these chemical warfare agents being used exists, and the proliferation of such chemical weapons continues, there is a need in the art to develop improved methods to detect and sample these hazards. The present invention addresses this and other needs.